Cyanohydrin process

ABSTRACT

Using cyanohydrin intermediates, 17-keto steroids are transformed to corticoids and 17α-acyl progesterones.

This is a continuation of Ser. No. 576,590, filed Feb. 3, 1984, now U.S. Pat. No. 4,500,461.

BACKGROUND OF THE INVENTION

There are a number of chemical processes for transformation of 17-keto steroids to the corresponding 17α-hydroxypregna steroids, see U.S. Pat. No. 4,041,055 and Tetrahedron Letters 22, 2005 (1971). Likewise, chemical processes are known for the transformation of 17-keto steroids to the corresponding corticoids, see U.S. Pat. No. 4,041,055, 4,342,702, 4,216,159, and Great Britain Pat. No. 2,086,907A.

The literature also sets forth processes for the transformation of the 17β-cyano-17α-hydroxy steroid (I) to the corresponding 17α-acyloxyprogesterone (VI) see P. deRuggieri, et al., J. Am. Chem. Soc. 81, 5725 (1959); J. C. Gasc, et al., Tetrahedron Letters 22, 2005 (1971); A. Belanger, Steroids 37, 361 (1981); and Japanese Pat. Nos. J5 7,062,296, J5 7,062,297, J5 7,062,299 and J5 7,062,300.

17β-Cyano-17α-hydroxy steroids (I) have been produced from the corresponding 17-keto steroids, see A. Ercoli, et al., J. Am. Chem. Soc. 75, 650 (1953); H. Heusser, et al., Helv. Chem. Acta 33, 1093 (1950); K. Meyer, Helv. Chim. Acta 29, 1580 (1946); K. Miescher, et al., Helv. Chim. Acta 21, 1317 (1938); H. Kuhl, et al., Steroids 28, 89 (1976), U.S. Pat. No. 3,496,169 and East German Pat. No. 147,669. Japanese Patents J5 7,062,296, J5 7,062,299 and J5 7,062,300 also include 17β-cyano-17α-hydroxyandrost-4,9(11)-dienes (IA). J. C. Gasc, et al., Tetrahedron Letters 22, 2005 (1971) reported the preparation of 19-nor-17β-cyano-17α-hydroxyandrost-5(10),9(11)-dienes.

17β-Cyano-17α-hydroxy steroids (I) are known where the 17α-hydroxy group is protected as an ester. See, for example, Helv. Chem. Acta 29, 1580 (1946) formula IV on p. 1582 and Helv. Chem. Acta 33, 1093 (1950) formula XIII on p. 1096. These compounds are also known where the 17α-hydroxy group is protected as an ether (II). See, for example, Steroids 37, 362 (1981) on p. 362 the TMS ether; J. Am. Chem. Soc. 81, 5725 (1959) on p. 5726 formula III as the THP ether; Tetra. Lett. 22, 2005 (1971) on p. 2007 formula IX as the TMS ether; and Japanese Pat. No. 7,062,296 for the butyl vinyl ether. U.S. Pat. No. 4,348,327 discloses 17β-cyano-17α-hydroxy steroids of the Δ⁴ -3-keto (A) and 3β-hydroxy-Δ⁵ (C) type which may or may not have methyl substitution at C₁₆ but which have no substitution in the C ring.

D. H. R. Barton, et al., J.C.S. Chem. Comm. 774 (1981) reported producing a 3β-O-substituted-Δ⁵ -enimide similar to the enimide (III) where the protecting group at 17α was acetate and the substituent on the enimide nitrogen at C₂₀ was --CHO. It should be noted that Barton, et al. did not produce his 3β-O-substituted-Δ⁵ -enimide from a 17β-cyano-17α-hydroxy steroid (II) but rather produced it by a different process from a 17(20)-unsaturated steroid.

R. B. Boar, et al., in J.C.S. Perkin I 1242 (1975) reported a 3β-acetoxy-Δ⁵ -20-acetyl enimide, starting with a pregnenolone derivative. While these compounds are somewhat similar to the enimide (III) of the present invention, the prior art compounds disclose an ester at the 17α position. The present process has the flexibility to produce the enimide (III) where the C₁₇ hydroxyl group is protected with an ether not an ester (acetate). The ester protecting group of the prior art processes has the disadvantage of being difficult to remove, whereas, the C₁₇ ethers of the present invention do not have that problem. Again, the enimide produced by Boar, et al. was produced from a different starting material by a process different than that of the present invention, i.e. the transformation of the 17-protected 17β-cyano-17α-hydroxy steroid (II) to the enimide (III).

The Δ²⁰ -enamide acylate (IV) is known where the steroid A-ring is 3β-hydroxy-Δ⁵ (C). Boar et al. produced their Δ²⁰ -enamide acylate from the corresponding 3β-acetyl-Δ⁵ -enimide by reaction with acetic acid containing trichloroacetic acid. See R. B. Boar, et al., J.C.S. Perkin I 1242 (1975). That compound had no substitution in the C-ring. The Δ⁴ -3-keto-(A) and Δ¹,4 -3-keto-(B)-Δ²⁰ -enamide acylates of the present inventions are easier to convert to the commercial corticoid products than is the compound dislosed by Boar, et al.

The Δ²⁰ -enamide (V) is a tautomer of the enimide (III). Boar, supra, disclosed a Δ²⁰ -enamide. That compound, compound IV on p. 1243, differs from the Δ²⁰ -enamide (V) in that at C₁₇ the group is an ester, whereas, the Δ²⁰ -enamides (V) must have an ether or hydroxy group at C₁₇. It has been found that use of ethers at C₁₇ (--OZ) permit the reaction of the 17-protected-17β-cyano-17α-hydroxy steroid (II) with Grignard reagents to produce the enimide (III) and further the Δ²⁰ -enamide (V). D. H. R. Barton, et al., J.C.S. Chem. Comm. 774 (1981) also discloses a Δ²⁰ -enamide 17-acetate, see compound (5). That compound further differs from the Δ²⁰ -enamides (V) of the present invention in that the substituent on the enamide nitrogen atom is an aldehyde (a formyl group) in Barton but is an acyl group in the present invention.

Boar, supra, discloses the transformation of an enimide-17-ester to a Δ¹⁶ -progesterone. The process of the present invention involves the transformation of an enimide-17α-ether (III, Z is not a hydrogen atom) or its tautomer, a Δ²⁰ -enamide-17-ether (V) to a Δ²⁰ -enamide 17-ester (IV), by an ether to ester exchange followed by hydrolysis to give a progesterone 17-acylate (VI). Boar discloses the hydrolysis of an enimide 17-acetate to a 20-keto-17-acetate (VI). The process of the present invention does not include the enamide 17-acetate of Boar or the process of its formation.

The oxazoline (IX), structure type, is known, see Great Britain Pat. No. 2,086,907A and J.C.S. Chem. Comm. 774 (1981). D. H. R. Barton, et al. in J.C.S. Chem. Comm. 774 (1981) transformed a Δ¹⁷(20) -20-amide to the oxazoline by reactions with a peracid whereas the process of the present invention starts with an enimide (III). Barton, et al. proposed a mechanism for his reaction involving an 17,20-epoxide and a 17α-hydroxy-20-enimide. However, none of the intermediates were isolated, identified or the mechanism proved. The 21-bromo-20-formaldimine 17-acetate (XVI) is disclosed by Barton, supra.

The 21-halo-Δ²⁰ -enamides (XX) are not known. The unhalogenated Δ²⁰ -enamide 17-acylate is known where the steroid A-ring is of the 3β-hydroxy-Δ⁵ series, see Boar and Barton supra. With ether substitution at C-17, the unhalogenated Δ²⁰ -enamide 17-ethers are unknown regardless of the substitution in the A-ring.

By the process of the present invention the Δ²⁰ -enamide (V) is converted into the corresponding 21-halo enimide (XV) in a one-step process. D. M. R. Barton, et al., JCS Chem. Comm., 774 (1981) disclosed the transformation of a Δ²⁰ -enamide (5), where the nitrogen was substituted with a formamide to the 21-bromo enimide (6) where both contain the 17-acetate.

The 21-halo enimide (XV) can be transformed to the 17α-hydroxy-21-bromo steroid (XIII) directly or indirectly via the 21-halo-Δ²⁰ -enamide (XX). Barton, supra, disclosed transformation of the 21-bromo steroid (7) to the 21-bromo-20-keto steroid (8) in which the ester at C-17 was not lost. The process of the present invention produces the free 17α-hydroxy-21-bromo-20-keto steroid (XIII).

BRIEF DESCRIPTION OF THE INVENTION

Disclosed are 17β-cyano-17α-hydroxy (IB), 17-protected-17β-cyano (IIB), enimide (III A-C), Δ²⁰ -enamide (V A-C), 21-haloenimide (XV A-C), 21-halo-Δ²⁰ -enamide (XX A-C), Δ²⁰ -enamide acylate (IV A,B), 17β-cyano-17α-hydroxy (IC) and 17β-cyano-17α-hydroxy (IA') steroids.

Disclosed is a process for the preparation of a C₃ protected form of an enimide (III A-C) which comprises (1) contacting a C₃ protected form of a 17-protected-17β-cyano-17α-hydroxy steroid (II A-C) with a methylating agent and contacting the product of step (1) with an acylating or silating agent.

Also disclosed in a process for the preparation of a C₃ protected form of a Δ²⁰ -enamide acylate (IV A-C) which comprises contacting a steroid selected from the group consisting of a C₃ protected form of an enimide (III A-C) or a C₃ protected form of a Δ²⁰ -enamide (V A-C) with a carboxylic acid of the formula R₁₇ COOH and an anhydride of the formula (R₁₇ CO)₂ O where R₁₇ is a hydrogen atom alkyl of 1 thru 5 carbon atoms, phenyl substituted with zero thru 2 chlorine atoms, trichloromethyl or trifluoromethyl groups.

Further disclosed is a process for the preparation of a C₃ protected form of a Δ²⁰ -enamide (V A-C) which comprises contacting a C₃ -protected form of an enimide (III A-C) with an acid or base.

Also disclosed is a process for the preparation of a C₃ protected form of an oxazoline (IX A-C) which comprises contacting a steroid selected from the group consisting of a C₃ protected form of an enimide (III A-C) or a C₃ protected form of a Δ²⁰ -enamide (V A-C) with an acid in an organic solvent or mixtures thereof.

Further disclosed is a process for the preparation of a steroid selected from the group consisting of a C₃ protected form of a 21-halo enimide (XV A-C) and a C₃ protected form of a 21-halo-Δ²⁰ -enamide (XX A-C) which comprises contacting a C₃ protected form of a Δ²⁰ -enamide (V A-C) with a halogenating agent.

Further disclosed is a process for preparing a C₃ protected form of a 17α-hydroxy steroid (XIII A-C) which comprises (1) contacting a steroid selected from the group consisting of a C₃ protected form of a 21-halo enimide (XV A-C) or a C₃ protected 21-halo-Δ²⁰ -enamide (XXA-C) with an aqueous acid.

DETAILED DESCRIPTION OF THE INVENTION

The 17-keto steroid starting materials are well known to those skilled in the art or can readily be prepared from known compounds by methods well known to those skilled in the art. These include Δ⁴ -3-keto (A), Δ¹,4 -3-keto (B) and 3β-hydroxy-Δ⁵ (C) steroids, see Chart G. The 17-keto starting materials can be substituted at C₆, C₉, C₁₁ and/or C₁₆, with R₆, R₉, R₁₁ and R₁₆ as defined infra.

The A-ring of the 17-keto starting material does not have to be protected to form the 17β-cyano-17α-hydroxy steroid (I). However, during the methylation reaction of transforming the 17-protected-17β-cyano-17α-hydroxy steroid (II) to the enimide (III) the A-ring must be protected.

For the Δ⁴ -3-keto steroids (A) the C₃ ketone is protected as the enol ether (Aa), ketal (Ab), or enamine (Ac) as is well known in the art, see Chart H. The preferred enol ether (Aa) is the methyl or ethyl ether. The preferred ketal (Ab) is the ethylene ketal. The preferred enamines are selected from the group consisting of pyrrolidine, morpholine and diethylamino amines. The enol ethers (a) are prepared by methods well known in the art, see J. Org. Chem. 26, 3925 (1961), Steroid Reactions, Edited by Carl Djerassi, Holden-Day, San Francisco, 1962, p. 42-45, and U.S. Pat. No. 3,516,991 (Preparation 1). The ketals (b) are also prepared by well known methods, see Steroid Reactions, supra,, p. 11-14. The 3-enamines (c) are also prepared by methods well known in the art, see U.S. Pat. No. 3,629,298 and Steroid Reactions, supra, p. 49-53.

The Δ¹,4 -3-keto steroids (B) are protected by reacting the 17-protected-17β-cyano-17α-hydroxy steroid (II) with a strong base such as LDA (lithium diisopropyl amide) to form an enolate represented by formula (Ba). The enolate is then methylated and acylated or silated to form the enimide (III). In the process the 3-enolate is also acylated or silated to give the 3-acylate or 3-silyl derivative of (Ba). In a subsequent workup and hydrolysis the A-ring enolate reforms the Δ¹,4 -3-keto (B) A-ring functionality.

The 3-hydroxy steroid (C) should have the 3β-hydroxyl group protected as the ether (Ca), see Chart H.

The C₃ protected forms (Aa, Ab and Ac) of the Δ⁴ -3-keto steroids (A), the C₃ protected forms (Ba) of the Δ¹,4 -3-keto steroids (B) and the C₃ protected forms (Ca and Cb) of the 3β-hydroxy steroids (C) are considered equivalent to the non-protected or free form (A, B and C) respectively since the C₃ protecting groups are readily removable to convert the C₃ protected forms (Aa, Ab, Ac, Ba and Ca) to the free or unprotected forms (A, B and C) respectively. In order to remove the C₃ protecting group from the Δ⁴ -3-keto steroids (A), Δ¹,4 -3-keto steroids (B) and 3β-hydroxy steroids (C) the reaction conditions would generally also remove the C₁₇ protecting group (Z) which is undesirable. Therefore, the C₃ protecting group remains during subsequent reactions not because it is needed per se but rather so as not to remove the (Z) protecting group. The C₃ and C₁₇ protecting groups can readily be removed, if desired, from the intermediates producing 17α-hydroxy-free-A-ring steroids.

The 17-keto steroid starting material is reacted with potassium cyanide and 2-cyano-2-hydroxypropane (acetone cyanohydrin) in an alcoholic solvent such as aqueous methanol to give the desired 17β-cyano-17α-hydroxy steroid (I) with high yields and stereospecificity as is known in the art. The reaction may be heated to 30°-50° if desired.

Before protecting the 17α-hydroxy group of the cyanohydrin (I), it is preferred that the C₃ function of the Δ⁴ -3-keto (A), Δ¹,4 -3-keto (B) or 3β-hydroxy-Δ⁵ (C) steroids be protected as discussed supra although the 17α-hydroxy group may be protected first. 17β-Cyano-17α-hydroxy steroids (I) are known were the 17α-hydroxy group is protected as an ether. See, Steroids 37, 362 (1981) on p 362 for the TMS ether; J. Am. Chem. Soc. 81, 5725 (1959) on p 5726 formula III as the THP ether; Tetra. Lett. 22, 2005 (1971) on p 2007 formula IX as the TMS ether and Japanese Pat. No. 7,062,296 for the butyl vinyl ether. The preferred 17α-protecting group is the ethoxy ethyl ether. Other suitable groups include THP, TMS, methoxymethyl, and butoxy ethyl ethers. The appropriate form of the 17β-cyano-17α-hydroxy steroid (I) is reacted with a reagent to form the desired ether protecting group (Z) such as ethoxy ethyl ether (EEE) using an acid catalyst such as pyridine hydrochloride, p-TSA, or in an inert solvent. Suitable solvents include toluene, SSB, cyclohexane, methylene chloride.

The enimide (III) and the Δ²⁰ -enamide (V) are tautomers. The 17-protected-17β-cyano-17α-hydroxy steroid (II) can be converted to both the enimide (III) and the Δ²⁰ -enamide (V). The 17-protected-17β-cyano-17α-hydroxy steroid (II) is converted to the enimide (III) by first reaction with a methylating agent. Addition of the methylating agent to the protected cyanohydrin (II) gives an intermediate imine which can be isolated, but it is preferred to acylate or silate the imine anion in situ by addition of an acylating or silating agent. The acylating agents are selected from the group consisting of acyl halides and acyl anhydrides of the formulas R₂₀ J, (R₂₀)₂ O, or R₂₀ "J. Suitable solvents for this reaction include ethers such as THF. The reaction is performed in the temperature range of about -30° to about 100°. Silating agents include J--Si(CH₃)₃ and J--Si(CH₃)₂ C(CH₃)₃.

Some methylating agents have greater Lewis acid properties or form better Lewis acids after methylation than other methylating agents. For example, methyl Grignard is a better Lewis acid than methyl lithium. Methylating agents such as methyl Grignard having sufficient Lewis acidity transform the initially formed enimide (III) to its tautomeric form the Δ²⁰ -enamide (V). Thus, with the methylating agents which are Lewis acids, such as methyl magnesium chloride the ratio of tautomeric products, the enimide (III) and Δ²⁰ -enamide (V) is time dependent. At short time periods the predominate product is the enimide (III). With time there is a decrease in the amount of enimide (III) and increase the amount of Δ²⁰ -enamide (V) to the point where predominately the Δ²⁰ -enamide (V) is present. Methylating agents which are poor Lewis acids include, for example, methyl lithium. The 17-protected-17β-cyano-17α-hydroxy steroid (II) is transformed to the enimide (III) if the methylating agent is methyl lithium and the imine anion formed is acylated or silated. Methylating agents which are or produce Lewis acids include Grignard reagents, for example, methyl magnesium bromide, chloride and iodide. For example, if the methylating agent is methyl magnesium bromide and the acylating agent is acetic anhydride, during the methylation/acylation step of transforming the 17-protected-17β-cyano-17α-hydroxy steroid (II) to the enimide (III) the methyl magnesium bromide is transformed to magnesium bromoacetate which is a (Lewis) acid and therefore the enimide (III) which is initially produced is transformed to the Δ²⁰ -enamide (V) without addition of another acid, see Example 7. If it is desired to isolate the enimide (III) the preferred methylating agent utilized in the methylation reaction is one that in situ will not be transformed to a Lewis acid. Methyl lithium is a methylating agent operable in effectuating the methylation reaction but will not form a Lewis acid and will permit isolation of the enimide (III), see Examples 5 and 31. The preferred methylating reagent is methyl lithium.

The enimide (III) is isomerized to its tautomer the Δ²⁰ -enamide (V) by reaction with an acid, or a base. Acids include Lewis acids, and carboxylic acids including polycarboxylic acids. It is preferred that the acid be acetic, propionic, benzoic or citric. The most preferred acid is acetic acid. Bases which are operable include guanidine and amidine bases, preferred are DBU and DBN.

The enimide (III) and Δ²⁰ -enamide (V) are tautomers. Both can be transformed to corresponding Δ²⁰ -enamide 17-ester (IV) by reaction with a carboxylic acid of the formula R₁₇ COOH and a carboxylic acid anhydride of the formula (R₁₇ CO)₂ O in the acid as solvent in the temperature range of about 0° to about 80° preferably at about 20° to about 25°. The reaction converts the protecting group "Z" at C-17 to the 17-ester (--OCOR₁₇) and with the enimide (III) also the enimide portion is tautomerized to the Δ²⁰ -enamide. It is preferred that R₁₇ is methyl, ethyl or phenyl, more preferably methyl. If R₁₇ is a hydrogen atom, trichloromethyl, trifluoromethyl or an equivalent substituent which makes the ester R₁₇ COO-- active, such ester (IV) may be selectively removed with mild base such as bicarbonate in methanol to give the 17α-hydroxy-Δ²⁰ -enamide (XVII). Likewise the 21-halo steroid (XI) can be converted to the 21-halo-17α-hydroxy corticoid (XIII). Alternatively, if R₁₇ is trimethyl silyl or other convenient silyl protecting group, such group may be removed with mild base as above, mild acid or fluoride ion producing the desired 17α-hydroxyl group in XVII.

The Δ²⁰ -enamide (V) can be transformed to the 17α-hydroxyprogesterone 17-ester (VI) by reaction with an appropriate esterifying agent such as an anhydride (R₁₇ CO)₂ O and the corresponding carboxylic acid R₁₇ COOH to produce the enamide acylate (IV) followed by addition of water to hydrolyze the enamide acylate (IV) to the 17α-hydroxyprogesterone 17-ester (VI).

The enimide (III) can be readily transformed to a 17α-hydroxyprogesterone 17-ester (VI) by reaction with the appropriate esterifying agent such as an anhydride (R₁₇ CO)₂ O or acid halide R₁₇ COJ in the corresponding acid, R₁₇ COOH, solvent. Preferred is acetic anhydride in acetic acid followed by water. This in situ acetylation avoids an often difficult separate acylation step on the hindered tertiary 17α-hydroxy group, see U.S. Pat. No. 4,154,748. If one were to start with androstenedione as the 17-ketone and perform the process of the present invention using acetic anhydride/acetic acid in converting the enimide (III) or Δ²⁰ -enamide (V) to the Δ²⁰ -enamide acylate (IV), one would obtain on hydrolysis 17α-hydroxyprogesterone 17-acetate (VI'A) as the 17α-hydroxyprogesterone 17-ester (VI), see Chart B. The 17α-hydroxyprogesterone 17-acetate (VI'A) can be transformed to 17α-hydroxy-6-methyleneprogestrone 17-acetate (VII) by the process of U.S. Pat. No. 3,642,840, Example 11 which can be transformed to 17α-hydroxy-6α-methylprogesterone 17-acetate (VIII) which is medroxyprogesterone by the process of U.S. Pat. No. 3,679,715, Example 1.

Alternatively, by starting with 6α-methylandrost-4-ene-3,17-dione (U.S. Pat. No. 3,166,551, Example 8) as the 17-keto steroid and performing the process of the present invention using acetic anhydride/acetic acid as the acetylating agent, 17α-hydroxy-6α-methylprogesterone 17-acetate (VIII) is obtained directly.

Just as the tautomers, the enimide (III) and Δ²⁰ -enamide (V) can both be transformed to the corresponding Δ²⁰ -enamide 17-ester (IV), likewise they both can readily be converted to the oxazoline (IX) by contacting the tautomer with an acid in an organic solvent. Mineral, Lewis, or organic acids are suitable. This would include sulfuric, hydrochloric, phosphoric and equivalent inorganic acids. Organic acids such as p-TSA and carboxylic (R₁₇ COOH) and dicarboxylic acids such as oxalic acid also are operable and are preferred. Suitable organic solvents include, for example, toluene, methylene chloride, ethyl acetate, methanol, ethanol, THF, diethyl ether, and mixtures thereof. The enimide (III) or Δ²⁰ -enamide (V) is contacted with the acid in the suitable organic solvent in a temperature range of about 20° to about 60°. The reaction mixture can be heated to the reflux temperature of the particular solvent used. The reaction is monitored by TLC and when complete the oxazoline (X) is isolated by means well known to those skilled in the art or can be halogenated without isolation.

The oxazline (IX) is a very useful intermediate in the production of corticoid diesters (XII), see Chart C. The oxazoline (IX) is halogenated to produce the halo-oxazoline (X) according to the procedure set forth in J.C.S. Chem. Comm. 774 (1981). The halooxazoline (X) is then readily converted by hydrolysis to the 21-halo steroid (XI) which is readily transformed to the pharmacologically useful corticoid diester (XII). Alternatively, the 21-halo enimide (XV) and 21-halo-Δ²⁰ -enamide (XX) is readily converted into halooxazoline (X) by contacting with an acid in an organic solvent.

The Δ²⁰ -enamide (V) can be readily converted to the corresponding 21-halo enimide (XV) by reaction with a halogenating agent selected from the group consisting of bromine, pyridine hydrobromide perbromide, NBS, dibromantin and NCS. The 21-halo enimide (XV) can be converted into its tautomer, 21-halo-Δ²⁰ -enamide (XX) under the influence of acid or base. Acids include organic carboxylic acids or polycarboxylic acids either as the solvent or in suitable organic solvents such as THF, toluene or methylene chloride. Acids may include Lewis acids such as BF₃ ˜etherate in organic solvent. Bases which are operable include amidine bases. Preferred are DBU and DBN. Under certain conditions the halogenation reaction becomes sufficiently acidic or basic to cause tautomerization of the 21-halo enimide (XV) to the 21-halo-Δ²⁰ -enamide (XX).

The 21-haloenimide (XV) and/or the 21-halo-Δ²⁰ -enamide (XX) can be hydrolyzed under acidic conditions to either the 21-halo steroid (XI) or the 21-halo-17α-hydroxy corticoid (XIII) depending on the conditions chosen. To prepare the corticoid diester (XII), the 21-haloenimide (XV) or its tautomer 21-halo-Δ²⁰ -enamide (XX) is first hydrolyzed with relatively high concentrations of aqueous acid with an organic cosolvent. The acids include mineral acids and carboxylic acids such as sulfuric, acetic, hydrochloric, etc. Organic cosolvents include methanol, toluene, methylene chloride. The 21-halo steroid (XI) is then converted to the corticoid diester (XII) by treatment with acylate ion in an organic solvent. The preferred conditions are treatment of the 21-halo steroid (XI) with potassium acylate in a mixture of DMF and toluene at 50°-100° for 6-18 hr. Specifically, to prepare the 17,21-diacetate (XII) the 21-halo steroid (XI) is treated with potassium acetate in DMF and toluene at 75° for 18 hr. The corticoid diesters (XII) are important pharmaceuticals, such as betamethasone dipropionate and diflorasone diacetate, and important intermediates such as Reichstein's Compound S 17,21-diacetate which is converted to hydrocortisone 17,21-diacetate by fermentation. The corticoid diesters (XII) can be converted to the commercially important 17,21-dihydroxy corticoids by the base hydrolysis. For example, hydrocortisone diacetate formula XII where R₁₁ is β-hydroxyl, R₆, R₉ and R₁₆ are hydrogen atoms can be converted to hydrocortisone by treatment with methanolic potassium carbonate at 20°-25°. Hydrocortisone can be converted to hydrocortisone 21-acetate by reaction with acetic anhydride in pyridine as is well known to those skilled in the art.

To prepare the commercially important corticoid 21-ester (XIV) directly from the 21-halo-Δ²⁰ -enamide (XX) or the 21-halo enimide (XV) the 21-halo compounds are hydrolyzed with dilute aqueous inorganic mineral acids such as sulfuric, hydrochloric or phosphoric in an organic solvent. The preferred conditions include treatment of (XV) or (XX) with dilute aqueous sulfuric acid in THF (Example 21) producing the 21-halo-17α-hydroxy corticoid (XIII). The 21-halo-17α-hydroxy corticoid (XIII) is converted to the corticoid 21-ester (XIV) by treatment with acylate ion as is well known to those skilled in the art.

DEFINITIONS

The definitions and explanations below are for the terms as used throughout the entire patent application including both the specification and the claims.

All temperatures are in degrees Centigrade.

TLC refers to thin-layer chromatography.

IR refers to infrared spectroscopy.

UV refers to ultraviolet spectroscopy.

CMR refers to C-13 magnetic resonance spectroscopy, chemical shifts are reported in ppm (δ) downfield from TMS.

NMR refers to nuclear (proton) magnetic resonance spectroscopy, chemical shifts are reported in ppm (δ) downfield from TMS.

TMS refers to tetramethylsilane.

MS refers to mass spectrometry expressed as m/e or mass/change unit.

When solvent pairs are used, the ratio of solvents used are volume/volume (v/v).

THF refers to tetrahydrofuran.

DMF refers to dimethylformamide.

SSB refers to an isomeric mixture of hexanes.

p-TSA refers to p-toluenesulfonic acid monohydrate.

Hal is a chlorine, bromine, iodine, atom.

NBS refers to N-bromosuccinimide.

NCS refers to N-chlorosuccinimide.

TMS refers to tetramethylsilyl

THP refers to tetrahydropyronyl

EEE refers to ethoxy ethyl ether [O--CH(CH₃)OCH₂ CH₃ ].

DBU refers to 1,8-diazabicyclo[5.4.0]undec-7-ene.

DBN refers to 1,6-diazabicyclo[3,4,0]non-5-ene.

LDA refers to lithium diisopropyl amide.

MEM refers to 2-methoxyethoxymethyl (CH₃ OCH₂ CH₂ OCH₂ O--).

Androstenedione refers to androst-4-ene-3,17-dione.

When the term "alkyl of thru carbon atoms" is used, it means and includes isomers thereof where such exist.

R refers to alkyl 1 thru 5 carbon atoms or a hydrogen atom with the proviso that the R's can be the same or different.

R_(a) is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine.

R_(g) is R_(a), a hydrogen atom or phenyl.

R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac); the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom.

R₆ is a hydrogen or fluorine atom or methyl group.

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom.

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond.

R₁₆ is a hydrogen atom or methyl group.

R₁₇ is a hydrogen atom alkyl of 1 thru 5 carbon atoms, phenyl substituted with zero thru 2 chlorine atoms, trichloromethyl or trifluoromethyl groups.

R₁₇ ' is a hydrogen atom or trifluoromethyl group.

R₂₀ is --OC--R₂₀ ' or --R₂₀ ".

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups.

R₂₀ " is --Si(CH₃)₃ or --Si(CH₃)₂ C(CH₃)₃.

R₂₁ is alkyl of 1 thru 5 carbon atoms or phenyl.

R₁₀₀ is alkyl of 1 thru 3 carbon atoms.

R₁₀₁ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine.

R₁₀₂ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine.

R₁₀₃ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine.

R₁₀₄ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine.

R₁₀₅ is a hydrogen atom or alkyl of 1 thru 3 carbon atoms.

R₁₀₆ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a secondary amine selected from the group consisting of piperidine, pyrrolidine or morpholine with the proviso that R₁₀₆ and R₁₀₇ combined cannot have more than 14 carbon atoms; R₁₀₆ and R₁₀₇ can be combined to form a secondary cyclic amine selected from the group consisting of piperidine, pyrrolidine and morpholine.

R₁₀₇ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a secondary amine selected from the group consisting of piperidine, pyrrolidine or morpholine with the proviso that R₁₀₆ and R₁₀₇ combined cannot have more than 14 carbon atoms; R₁₀₆ and R₁₀₇ can be combined to form a secondary cyclic amine selected from the group consisting of piperidine, pyrrolidine and morpholine.

J is a chlorine, bromine or iodine atom.

M is a lithium, sodium, potassium, magnesium or calcium atom.

Q refers to a hydrogen atom, or alkyl of 1 thru 5 carbon atoms.

W is a TMS, THP, or EEE group.

X refers to a hydrogen atom or nothing.

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group.

Z' is a hydrogen atom or Z.

˜indicates that the attached atom or group can be in either the α or β configurations. is a single or double bond.

EXAMPLES

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, practice the present invention to the fullest extent. The following detailed examples describe how to prepare the various compounds and/or perform the various processes of the invention and are to be construed as merely illustrative, and not limitations of the preceding disclosure in any way whatsoever. Those skilled in the art will promptly recognize appropriate variations from the procedures both as to reactants and as to reaction conditions and techniques.

EXAMPLE 1 17β-Cyano-17α-hydroxyandrost-4-en-3-one (IA)

Acetone cyanohydrin (82 ml), potassium cyanide (1 gm) and water (2 ml) are added to a slurry of androst-4-en-3,17-dione (0.80 g) in methanol (400 ml) and water (40 ml) at 35°. The reaction becomes homogeneous and on continued stirring a heavy slurry develops. After 3 hours, 120 ml of water is added dropwise, and the slurry allowed to stir overnight at 20°-25°. The slurry is then cooled in an ice bath, filtered, and the solids washed with methanol/water (1/1). The solvents are dried under reduced pressure to give 70.4 g of the title compound. An additional 13.17 g of product is isolated from the mother liquor on partial evaporation, m.p.=159°-160.5°; [α]^(D) (c=1, CHCl₃)=+145.9°; MS=313, 298, 286, 245 and 124 m/e; NMR (CDCl₃)=1.00, 1.20, 3.5 and 5.72 δ.

EXAMPLE 2 17β-Cyano-17α-hydroxyandrosta-4,9(11)-dien-3-one (IA)

Acetone cyanohydrin (5 ml) and sufficient potassium cyanide to adjust the pH to 9.9 is added to a slurry of androst-4,9(11)-dien-3,17-dione (0,5 g), methanol (40 ml) and water (2.5 g) at 40°. The reaction becomes homogeneous followed by precipitation of the product. After 3.5 hours, water (7.5 ml) is added dropwise and the reaction is allowed slowly to stir at 20°-25° overnight. The slurry is cooled on an ice bath, filtered, the solids washed with methanol/water (1/1) and dried under reduced pressure to give the title compound (4.54 g); [α]^(D) (c=1, CHCl₃)=+118°; MS=311, 296 and 284 m/e; NMR (CDCl₃)=0.97, 1.37, 2.9, 5.5 and 5.70 δ.

EXAMPLE 3 17β-Cyano-17α-hydroxyandrost-5-en-3-ethylidine ketal (IAb)

p-TSA (100 mg) is added to a mixture of 17β-cyano-17α-hydroxyandrost-4-en-3-one (IA, Example 1, 5 g) in methylene chloride (50 ml), ethylene glycol (5 ml) and trimethylorthoformate (2.5 ml). The resulting mixture is stirred 2 hours at 20°-25°. The reaction mixture is concentrated to approximately 20 ml at atmospheric pressure. Triethylamine (0.2 ml) is added, the mixture extracted with phosphate buffer (pH 7) and the organic phase concentrated to a solid. The solid is crystallized from methanol to give the title compound (5.1 g); m.p.=229.5°-230.5°; [α]^(D) (c=1, CHCl₃)=+4.2°; MS=357, 342, 330 and 302 m/e; NMR (CDCl₃)=0.93, 1.10, 3.3, 3.97 and 5.3 δ.

EXAMPLE 4 17β-Cyano-17α-(α-ethoxyethyl)-etherandrost-5-en-3-ethylidine ketal (IIAb)

A mixture of 17β-cyano-17α-hydroxyandrost-5-en-3-ethylidine ketal (IAb, Example 3, 3.57 g) in methylene chloride (10 ml) containing ethyl vinyl ether (2 ml) and pyridine hydrochloride (100 mg) is heated in a sealed bottle at 40° for 2.5 hours and at 40° for 4 hours. Triethylamine (0.2 ml) is added and the reaction washed with phosphate buffer (pH 7), water and then dried over sodium sulfate, filtered and the filtrate concentrated under reduced pressure to give the title compound (4.61 g) as an oily mixture of diastereomers; NMR (CDCl₃)=0.98, 1.04, 3.5, 3.94, 5.0 and 5.2 δ.

EXAMPLE 5 17α-(α-ethoxyethyl)-ether-20-acetyliminopregn-5-en-3-ethylidine ketal (IIIAb)

Methyl lithium (1.5M, 1.2 ml) is added to a mixture of 17β-cyano-17α-(α-ethoxy ethyl)-ether-androst-5-en-3-ethylidine (IIAb, Example 4, 550 mg) and toluene (3.5 ml) at 0° . After 2.5 hours at 0° the reaction is quenched by adding acetic anhydride (1 ml) and toluene (1 ml) resulting in a stirrable gel. Aqueous phosphate buffer (pH 7) is added, the phases are separated and the the lower aqueous phase is backwashed with ethyl acetate. The combined organic phases are backwashed with sodium bicarbonate (5%), phosphate buffer, dried over sodium sulfate and concentrated to give the title compound (643 ml) as an oil; NMR (CDCl₃)=0.71, 1.02, 1.92, 2.00, 2.12, 3.4, 3.93, 4.7 and 5.3 δ; MS=487, 415 and 297 m/e.

EXAMPLE 6 17α-(α-ethoxyethyl)-ether-20-acetylaminopregna-5,20-dien-3-ethylidine ketal (VAb)

17α-(α-ethoxyethyl)-ether-20-acetylaminopregna-5-en-3-ethylidine ketal (IIIAb, Example 5, 3 mM) is stirred in glacial acetic acid (2 ml) for 1.5 hour at 20°-25°. Toluene is added and the organic diluents removed under reduced pressure. Additional toluene is added and the mixture washed with sodium bicarbonate (5%), phosphate buffer and the organic phase is dried over sodium sulfate and concentrated under reduced pressure to give the title compound (1.7 g) as an oil, NMR (CDCl₃)=0.69, 1.02, 2.03, 3.4, 3.94, 4.6, 4.82, 4.97, 5.3, 5.84, 6.03 and 6.8 δ.

EXAMPLE 7 17α-(α-ethoxyethyl)-ether-20-acetylaminopregna-5,20-dien-3-ethylidine ketal (VAb)

Methyl magnesium bromide in ether (2.85M, 7 ml) is added to a mixture of 17β-cyano-17α-(α-ethoxyethyl)-etherandrost-5-en-3-ethylidine ketal (IIAb, Example 4, 10 mM) in toluene (25 ml) and the mixture heated at 55° for 6 hours in a sealed pressure bottle. The mixture is then dissolved in THF (10 ml) and is added to toluene (20 ml) containing acetic anhydride (3 ml) which had been previously cooled to 0°. This mixture is allowed to warm to 25° during a 1/2 hour stirring period after which it is extracted with phosphate buffer (twice), dried over sodium sulfate, concentrated to give the title compound as an oil. This product is spectroscopically and chromatographically identical to the product of Example 6.

EXAMPLE 8 17α-Acetoxy-20-acetylaminopregna-5,20-dien-3-ethylidine ketal (IVAb)

17β-Cyano-17α-(α-ethoxy ethyl)-ether androst 5-en-3-ethylidine ketal (VAb, Example 7) is dissolved in glacial acetic acid (10 ml) and acetic anhydride (5 ml) and the mixture stirred for 24 hours at 20°-25°. The reaction mixture is then added to aqueous phosphate buffer and extracted with ethyl acetate. The phases are separated and the organic phase is washed with water, sodium bicarbonate (5%), water again, dried over sodium sulfate and concentrated to give the title compound as an oil; NMR (CDCl₃)=0.73, 1.07, 2.08, 3.97, 5.00, 5.3, 5.8 and 6.6 δ; CMR (CDCl₃)=169.78, 140.23, 138.85, 121.68, 109.35, 104.01, 93.59 and 64.36 δ; MS=398 (m+1); IR (CHCl₃)=1730, 1685 cm⁻¹.

EXAMPLE 9 17α-Acetoxy-20-acetylaminopregna-5,20-dien-3-ethylidine ketal (IVAb)

Following the general procedure of Example 8 and making noncritical variations, but starting with 17α-(α-ethoxy ethyl)-ether-20-acetylaminopregn-5-en-3-ethylidine ketal (IIIAb, Example 5) the title compound is obtained as an oil identical in all respects to the product of Example 8.

EXAMPLE 10 17α-Acetoxyprogesterone (VIA)

Acetic acid (1.5 ml) and water (0.5 ml) are added to 17α-acetoxy-20-acetylaminopregna-5,20-dien-3-ethylidine ketal (IVAb, Example 8, 0.5 mM) in acetic acid (0.66 ml) and acetic anhydride (0.34 ml). The reaction mixture is heated at 55° for approximately 18 hours. TLC (ethyl acetate/toluene:3/7) shows the hydrolysis to be complete to approximately a 90/10 mixture of 17α-acetoxyprogesterone and 17α-hydroxyprogesterone. Acetic anhydride (0.75 ml) and p-TSA (30 mg) are added and heating continued for 2 hours at 50°. Water (0.3 ml) is added and the heating is continued at 50° for 7.5 hours. Water (2 ml) is then added resulting in a precipitate which is filtered and dried to give the title compound.

EXAMPLE 11 17R,2'-Methyl-4'-methylenespiro-3-ethylenedioxyandrost-5-en-17,5'(4'H)-oxazole (IXAb)

Acetic acid (5 ml) and acetic anhydride (0.4 ml) are added to 17α-(α-ethoxyethyl)-ether-20-acetylaminopregn-5-en-3-ethylidine ketal (IIIAb, Example 5, 10 mM) and the mixture heated to 55°. After 1 hour of heating at 55°, additional acetic acid (5 ml) and acetic anhydride (0.4 ml) are added and the heating continued for an additional 2.5 hours. The reaction mixture is cooled, the solid filtered, washed with diethyl ether and dried to give the title compound (1.45 g), m.p.=199°-209°; NMR (CDCl₃)=0.81, 1.03, 2.04, 3.86, 4.65 and 5.30 δ; MS (CI)=398 (M+1).

EXAMPLE 12 17R,2'-Methyl-4'-methylenespiro-3-ethylenedioxyandrost-5-en-17,5'(4'H)-oxazole (IXAb)

Methanol (2 ml) and p-TSA.H₂ O (2 ml) is added to 17α-(α-ethoxy ethyl)-ether-20-acetylaminopregn-5,20-dien-3-ethylidine ketal (VAb, Example 6, 200 ml) and the mixture heated to 70° for 40 minutes. Analysis by TLC and NMR shows that the product is mostly the title compound along with small amounts of 3-methyl enol ether and Δ4-3-keto analogues.

EXAMPLE 13 17R,2'-Methyl-4'-bromomethylenespiro-3-ethylenedioxyandrost-5-en-17,5'(4'H)-oxazole (XAb)

Pyridium bromide perbromide (3 ml) is added to 17R,2'-methyl-4'-methylenespiro-3-ethylenedioxyandrost-5-en-17,5'(4'H)-oxazole (IXAb, Example 11, 50 ml) in methylene chloride (1 ml) and pyridine (0.05 ml) at 0°. TLC shows a single less polar product. A few drops of sodium bisulfite (1M) and acetic acid are added. The phases are separated and the orgaic phase is washed with water, dried over sodium sulfate, and concentrated to give the title compound, NMR (CDCl₃)=0.92, 1.03, 2.17, 3.93, 5.27 and 5.33 δ; MS (CI,CH₄)=476, 478 (M+1), 396.

EXAMPLE 14 21-Bromo-17α-acetoxyprogesterone (XIA)

17R,2'-Methyl-4'-bromomethylenespiro-3-ethylenedioxyandrost-5en-17,5'(4'H)-oxazole (XAb, Example 13). The product from Example 13 is dissolved in a solution of acetic acid (0.75 ml) and water (0.25 ml) and heated overnight at about 105° in a sealed vial. The reaction mixture is then added dropwise to a solution of phosphate buffer (pH 7) giving the title compound, NMR (CDCl₃)=0.72, 1.17, 2.10, 3.90 and 5.67 δ.

EXAMPLE 15 21-Bromo-17α-(α-ethoxyethyl)-ether-20-acetylaminopregna-5-en-3-ethylidine ketal (XVAb)

Pyridinium hydrobromide perbromide (0.29 g) is added to 17α-(α-ethoxy ethyl)-ether-20-acetylaminopregna-5,20-dien-3-ethylidine ketal (VAb, Example 6, 411 mg) in a mixture of methylene chloride (3 ml), methanol (0.75 ml), water (0.12 ml) and triethylamine (0.26 ml) at 0°. The reaction is complete after about 5 minutes. Methylene chloride and water are added, the phases separated, the organic phase is dried over sodium sulfate and concentrated to give the title compound, NMR (CDCl₃)=0.77, 0.83, 1.03, 2.27, 2.29, 3.9 and 5.27 δ; MS (CI)=566 and 568 (m+1) and 550.

EXAMPLE 16 21-Bromo-17α-acetoxy-20-acetylaminopregn-5-en-3-ethylidine ketal (XVIAb)

Pyridinium hydrobromide perbromide (100 ml) is added to 17α-acetoxy-20-acetylaminopregn-5,20-diene-3-ethylidine ketal (IVAb, Example 8, 140 ml), and the mixture is stirred for 15 minutes at 0°. Phosphate buffer (pH 7) is added, the phases are separated and the organic phase is washed with sodium bicarbonate (5%), water, dried over sodium sulfate and concentrated to an oil. The oil is chromatographed over silica gel (10 gm) eluting with acetone/methylene chloride: 5/95, the appropriate fractions are pooled and concentrated to give the title compound; NMR (CDCl₃)=0.82, 1.03, 2.07, 2.30, 3.9, and 5.28 δ; MS (CI)=536 and 538 (m+1).

EXAMPLE 17 21-Bromo-17α-acetoxy-20-acetylaminopregna-5,20-dien-3-ethylidine ketal (XXIAb)

DBW (0.5 ml) is added to 21-Bromo-17α-acetoxy-20-acetylaminopregn-5-en-3-ethylidine ketal (XVIAb, Example 16, 3.16 g) and toluene (8.5 ml). After 1/2 hour the tautomerization is complete. The reaction mixture is washed with phosphate buffer (pH 7), filtered through magnesol, dried over sodium sulfate and concentrated to give the title compound; NMR (CDCl₃)=0.72, 0.77, 1.03, 2.03, 2.06, 3.93, 4.52, 4.80, 5.3, 6.3, 6.4, 6.5 and 7.6 δ.

EXAMPLE 18 21-Bromo-17α-acetoxyprogesterone (XIA)

Following the general procedure of Example 19 and making noncritical variations, but starting with 21-bromo-17α-acetoxy-20-acetylaminopregna-5,20-dien-3-ethylidine ketal (XXIAb, Example 17), the title compound is obtained.

EXAMPLE 19 21-Bromo-17α-acetoxyprogesterone (XIA)

Acetic acid (1.5 ml) and water (0.5 ml) are added to 21-bromo-17α-acetoxy-20-acetylamino-pregn-5-en-3-ethylidine ketal (XVIAb, Example 16, 38 mg). The mixture is heated in a sealed vial at 108° for one hour. Toluene is added to the cooled reaction mixture, the phases separated, the organic phase washed with water, dried over sodium sulfate and concentrated under reduced pressure to give the title compound, NMR (CDCl₃)=0.73, 1.20, 2.10, 3.93, and 5.67δ.

EXAMPLE 20 17α,21-Dihydroxypregn-4-en-3,20-dione 17,21-diacetate (XIIA)

21-Bromo-17α-acetoxyprogesterone (XIA, Example 19, 50 mg) is dissolved in toluene (0.3 ml) and DMF (0.3 ml) with acetic acid (4 micro liters) and stirred with potassium acetate (19 mg) at 70° in a sealed vial for 221/2 hours. Additional toluene is added and the mixture extracted with water. The organic phase is dried over sodium sulfate and concentrated under reduced pressure to give the title compound. NMR (CDCl₃) 0.76, 1.20, 2.07, 2.13, 4.55, 5.85 and 5.67 δ.

EXAMPLE 21 21-Bromo-17α-hydroxyprogesterone (XIIIA)

Sulfuric acid (1N, 1 drop) is added to 21-bromo-17α-(α-ethoxy ethyl)-ether-20-acetylaminopregn-5-en-3-ethylidine ketal (XVAb, Example 15, 50 mg) in THF (0.6 ml) and water (0.2 ml). This mixture is stirred at 20°-25° for 18 hours and then heated at 60° for 17.5 hours to give the title compound, NMR (CDCl₃)=0.73, 1.20, 4.22, and 5.70 δ.

EXAMPLE 22 21-Bromo-17α-hydroxypregn-5-en-20-one 3-ethylidine ketal (XIIIAb)

Sulfuric acid (1N, 4 drops) is added to 21-bromo-17α-(α-ethoxy ethyl)-ether-20-acetylaminopregn-5-en-3-ethylidine ketal (XVAb, Example 15, 220 mg) in THF (2.5 ml) and water (0.8 ml). The mixture is stirred at 20°-25° for four days. Toluene is added and the reaction mixture washed with buffer (pH 7), dried over sodium sulfate and concentrated to an oil. The oil is chromatographed on a silica gel column diluting with ethyl acetate/hexane: 1/1. The appropriate fractions are pooled and concentrated to give the title compound, NMR (CDCl₃)=0.68, 1.02, 3.91, 4.25, and 5.30δ; MS (CI)=453, 455 (m+1), 435, 437, 373, 357, and 355.

EXAMPLE 23 21-Bromo-17α-hydroxyprogesterone (XIIIA)

21-Bromo-17α-hydroxypregn-5-en-20-on-3-ethylidine ketal (XIIIAb, Example 22) is converted to the title compound by heating the reaction mixture of Example 22 to 60° for about 18 hours instead of stirring at 20°-25° for four days.

EXAMPLE 24 17β-Cyano-3β,11β,17α-trihydroxyandrosta-3,5-diene-3-methyl ether (IAa)

Pyridine hydrochloride (120 mg), methanol (20 ml) and trimethyl orthoformate (3 ml) are added to 17β-cyano-11β,17α-dihydroxyandrost-4-en-3-one (IA, Example 25, 6.58 g). The mixture is heated at reflux overnight, cooled to crystallize and reheated for 1.5 hours at 50°-55°. The solid is filtered, washed with buffer (pH 7), water and dried to give the title compound.

EXAMPLE 25 17β-Cyano-11β,17α-dihydroxyandrost-4-en-3-one (IA)

11β-Hydroxyandrost-4-en-3,17-dione (OA, 5 gms) is added to acetone cyanohydrin (10 ml) and methanol (20 ml). A saturated aqueous solution of potassium cyanide (5 ml) is added to the steroid mixture. The mixture is stirred for 21/2 hours during which time the product precipitates. The precipitate is filtered, washed with buffer (pH 7, 25 ml) and water to give the title compound. This material is purified by chromatography on silica gel (20% ethyl acetate-chloroform). The appropriate fractions are pooled and concentrated to give a solid which is recrystallized from ethyl acetate to give the title compound, [α]_(D) ²⁰ +158° (DMSO); IR (KBr)=3500, 3250, 2830-3010, 2220, 1650, cm⁻¹ ; NMR (CDCl₃ /CD₃ OD, 1:1)=1.2, 1.47, 4.2, 4.4 and 5.6 δ.

EXAMPLE 26 17β-Cyano-11β,17α-dihydroxyandrosta-1,4-dien-3-one (IB)

11β-Hydroxyandrosta-1,4-diene-3,17-dione (OB, 5 gms) is mixed with acetone cyanohydrin (10 ml) and methanol (10 ml). A saturated aqueous solution of potassium cyanide (10 ml) is added and after 5 minutes, a solution is obtained. The reaction mixture is stirred for one hour, during which time, the product is crystallized. A buffer (pH 7, 50 ml) is added and the slurry filtered. The crystals are washed with buffer, water and dried. The solid material is recrystallized from ethyl acetate to give the title compound [α]_(D) +90° (DMSO); IR (KBr)=3365, 3010, 2850, 2220, 1650, 1600, 1570; cm⁻¹ : NMR (CDCl₃ /CD₃ OD, 1:1)=1.23, 1.50, 4.18, 4.4, 5.94, 6.18 and 7.33 δ.

EXAMPLE 27 17β-Cyano-11β,17α-dihydroxy-6α-methylandrost-4-en-3-one (IA)

11β-Hydroxy-6α-methylandrost-4-ene-3,17-dione (OA, 0.51 gms) is treated with acetone cyanohydrin (1 ml) and methanol (1 ml) and saturated potassium cyanide (1 ml). After several hours, buffer (pH 7, 5 ml) is added and the precipitate filtered, washed with water and dried to give a solid. This material is slurried in glacial acetic acid, filtered, washed with acetic acid water and dried to give the title compound [α]_(D) +117° (DMSO); IR (KBr)=3410, 3080, 2840, 2225, 1655 and 1602; cm⁻¹ ; NMR (CDCl₃ /CD₃ OD, 1:1) 1.08, 1.22, 1.47, 4.33, 4.40 and 5.65 δ.

EXAMPLE 28 17β-Cyano-11β,17α-dihydroxy-6α-methylandrosta-1,4-dien-3-one (IB)

11β-Hydroxy-6α-methylandrosta-1,4-diene-3,17-dione (OB, 2.59 gms) is reacted with acetone cyanohydrin (5 ml), methanol (5 ml), and a saturated cyanide solution (5 ml). After three hours of mixing, the reaction is complete as measured by TLC (toluene/ethyl acetate:20/80). The reaction mixture is diluted with buffer (pH 7, 20 ml), giving a solid which is filtered, washed with water, and dried to give the title compound [α]_(D) +85° (DMSO); IR (KBr) 3390, 3300, 3010, 2840, 2230, 1650, 1625, 1580, cm⁻¹ ; NMR (CDCl₃ /CD₃ OD, 1:1)=1.1, 1.22, 1.48, 4.40, 5.95, 6.2, and 7.30 δ.

EXAMPLE 29 17β-Cyano-3β,11β,17α-trihydroxyandrosta-3,5-diene 3-methyl ether 17α-(α-ethoxyethyl)-ether (IIAa)

17β-Cyano-3β,11β,17α-trihydroxyandrosta-3,5-diene 3-methyl ether (IAa, Example 24, 343 ml) toluene (1 ml), methylene chloride (0.1 ml), ethyl vinyl ether (0.6 ml), and pyridine hydrochloride (12 mg) are heated overnight in a small pressure vessel at 85°. TLC (20% ethyl acetate-chloroform) shows the reaction to be complete, containing a less polar product. Triethylamine (0.3 ml), buffer (pH 7, 5 ml) and toluene (5 ml) are added and mixed. The layers are separated, the organic phase dried and organic solvents removed to give the title compound.

EXAMPLE 30 11β,17α-Hydroxypregn-4-ene-3,20-dione (XXII)

17β-Cyano-3β,11β,17α-trihydroyandrosta-3,5-diene 3-methyl ether 17α-(α-ethoxyethyl)-ether (IIAa, Example 29), methyl lithium (1.5N, 3 ml) are allowed to react at 20°-25° overnight. Water (3 ml), acetic acid (3 ml) and methanol (10 ml) are added. The reaction mixture is taken up in methylene chloride (50 ml) and washed with water (50 ml). The organic phase is separated and washed twice with sulfuric acid (2N, 25 ml) followed by water. The organic solvent is removed and replaced with a mixture of ethanol, concentrated hydrochloric acid and water and allowed to stand overnight. Methylene chloride is added, the mixture washed with water, the organic solvents removed, and the material crystallized from ethyl acetate to give a-crystalline product which is identical with 11β,17α-dihydroxyprogesterone.

EXAMPLE 31 17α-(α-ethoxyethyl)-ether-20-trifluoroacetylaminopregn-5-ene 3-ethylidine ketal (IIIAb)

A solution of 17β-cyano-17α-(α-ethoxyethyl)-etherandrost-5-ene-3-ethylidine ketal (IIAb, Example 4, 3.5 mmole) in toluene (12.5 ml) is cooled to 0°. Methyl lithium (1.6M, 2.95 ml) in diethyl ether is added (dropwise) over a period of 4 hours. The reaction is stirred an additional 3 hours at 0° and then quenched at -35° with pyridine (0.76 ml) and trifluoroacetic hydride (1 ml). The reaction mixture is extracted 3 times with phosphate buffer (pH 7), the organic layer is dried over sodium sulfate and concentrated to give the title compound. NMR (CDCl₃) 0.71, 1.01, 1.20, 2.05, 2.11, 3.40, 3.90, 4.63 and 5.28 δ.

EXAMPLE 32 17α-(α-ethoxyethyl)-ether-20-trifluoroacetylaminopregna-5,20-diene 3-ethylidine ketal (VAb)

DBU (50 micro liters, 0.3 mmole) is added to 17α-(α-ethoxy ethyl)-ether-20-trifluoroacetylaminopregna-5-ene-3-ethylidine ketal (IIIAb, Example 31, 3.5 mmole) in toluene (10 ml) and stirred at 20°-25° for 70 minutes. The mixture is then extracted 3 times with phosphate buffer (pH 7), dried over sodium sulfate and concentrated to an oil. NMR (CDCl₃) 0.70, 1.03, 1.23, 3.47, 3.90, 4.70, 5.04, 5.18, 5.29, 5.88 and 6.17 δ.

EXAMPLE 33 21-Bromo-17α-(α-ethoxyethyl)-ether-20-trifluoroacetylaminopregn-5-en 3-ethylidine ketal (XVAb) and 21-Bromo-17α-(α-ethoxyethyl)-ether-20-acetylaminopregna-5,20-diene 3-ethylidine ketal (XXAb)

17α-(α-ethoxyethyl)-ether-20-trifluoroacetylaminopregna-5,20-diene-3-ethylidine ketal (VAb, Example 32, 190 mg) is dissolved in methylene chloride (0.5 ml) and methanol (0.125 ml) with triethylamine (61 micro liters) and water (20 micro liters). The mixture is cooled to 0°. Pyridinium hydrobromide perbromide (0.105 g) is added incremently. The reaction mixture is stirred at 0° for 2 1/5 hours and then extracted with phosphate buffer (pH 7). The organic layer is dried over sodium sulfate and concentrated to give the title compounds. NMR (CDCl₃) 0.71, 0.75, 0.82, 1.03, 1.27, 3.43, 3.93, 4.33, 4.70, 5.3, 6.47 and 6.53 δ.

EXAMPLE 34 21-Bromo-17α-hydroxyprogesterone (XIIIA) and 21-Bromo-17α-trifluoroacetylprogesterone (XIA)

21-Bromo-17α-(α-ethoxyethyl)-ether-20-trifluoroacetylaminopregn-5-en-3-ethylidine ketal (XVAb, Example 33) and 21-bromo-17α-(α-ethoxyethyl)-ether-20-acetylaminopregna-5,20-diene-3-ethylidine ketal (XXAb, Example 33) as an oil (110 ml) containing a mixture of XVAb and XXAb is dissolved in THF (1.2 ml) with sulfuric acid (1N, 0.2 ml). The mixture is heated at 54° for 9 hours. The mixture is extracted into ethyl acetate, washed with phosphate buffer (pH 7) to neutrality. The mixture is then concentrated to an oil which as shown by NMR analysis contains the title compound.

EXAMPLE 35 21-Bromo-17α-hydroxyprogesterone (XIIIA)

21-Bromo-17α-hydroxyprogesterone (XIIIA, Example 34) and 21-bromo-17α-trifluoroacetylprogesterone (XIA, Example 34) as an oil containing 160 mg of a mixture of XIIIA and XIA is dissolved in methanol (6.0 ml) and water (1 ml) with sodium bicarbonate (172 mg). The mixture is stirred at 20°-25° for 2 hours. The mixture is extracted with methylene chloride, the methylene chloride extract is concentrated to give the title compound. NMR (CDCl₃) 0.73, 1.20, 4.09, 4.37 and 5.69 δ.

EXAMPLE 36 17R, 2'-Methyl-4'-bromomethylenespiro-3-ethylenedioxyandrost-5-en-17,5'(4'H)-oxazole (XAb)

21-Bromo-17α-(α-ethoxyethyl)-ehter-20-acetylaminopregna-5,20-diene 3-ethylidine ketal (XXAb, Example 33, 43 mg) is stirred in ethanol (1.5 ml) with boron trifluoride etherate (0.076 mM) at 20°-25° for 3 hr. The reaction is quenched with phosphate buffer (pH 7) and extracted into ethyl acetate. NMR and TLC confirmed the identity of the title compound.

EXAMPLE 37 17α-(α-ethoxyethyl)-ether-20-trimethylacetylaminopregna-5,20-diene 3-ethylidine ketal (VAb)

A 2:1 mixture of 17α-(α-ethoxyethyl)-ether-20-trimethylacetylaminopregna-5,20-diene 3-ethylidine ketal (VAb) and 17α-(α-ethoxyethyl)-ether-20-trimethylacetyl-aminopregn-5-ene 3-ethylidine ketal (IIIAb) is dissolved in toluene (5 ml) and THF (1 ml) and stirred with several mg of magnesium bromide under nitrogen at 20°-25°. After 16 hr all of (IIIAb) is epimerized to (VAb).

EXAMPLE 38 21-Bromo-17α-hydroxyprogesterone 17-acetate (XIA)

21-Bromo-17α-(α-ethoxyethyl)-ether-20-acetylaminopregn-5-ene 3-ethylidine ketal (XVAb), Example 33, 100 mg) is stirred in methanol and sulfuric acid (1N, 0.4 ml) for 19 hr at 20°-25° followed by 46° for 3 days giving the title compound.

EXAMPLE 39 21-Bromo-17α-hydroxyprogesterone 17-acetate (XIA)

21-Bromo-17α-(α-ethoxyethyl)-ether-20-acetylaminopregna-5,20-diene 3-ethylidine ketal (XXAb, Example 33, 100 mg) is stirred in acetic acid (1 ml) and water (0.3 ml) at 60° for 18 hr to give the title compound. ##STR1##

ENUMERATED EMBODIMENTS

The following Enumerated Embodiments further describe the applicant's invention.

1. A 17β-cyano-17α-hydroxy steroid of the formula ##STR2## and C₃ protected forms thereof where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

is a single or double bond; and

˜indicates that the attached atom or group can be in either the a or β configurations.

2. A 17β-cyano-17α-hydroxy steroid according to Enumerated Embodiment 1 where R₉ is nothing, R₁₁ is a hydrogen atom and the C-ring contains a Δ⁹(11) double bond.

3. A 17β-cyano-17α-hydroxy steroid according to Enumerated Embodiment 1 which is seleted from the group consisting of 17β-cyano-11β,17α-dihydroxyandrosta-1,4-dien-3-one and 17β-cyano-11β,17α-dihydroxy-6α-methylandrosta-1,4-dien-3-one.

4. A 17-protected-17β-cyano-17α-hydroxy steroid of the formula ##STR3## and C₃ protected forms thereof where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group;

is a single or double bond; and

˜indicates that the attached atom or group can be in either the a or β configurations.

5. A steroid selected from the group consisting of an enimide of the formula ##STR4## an Δ²⁰ -enamide of the formula ##STR5## and C₃ protected forms thereof where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

R₂₀ is --OC--R₂₀ ' or --R₂₀ ";

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups;

R₂₀ " is --Si(CH₃)₃ or 13 Si(CH₃)₂ C(CH₃)₃ ;

X refers to a hydrogen atom or nothing;

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group;

is a single or double bond; and

˜ indicates that the attached atom or group can be in either the a or β configurations.

6. A steroid according to Enumerated Embodiment 5 where the Δ⁴ -3-keto steroid (A) is protected as the ##STR6## where the Δ¹,4 -3-keto steroid (B) is protected as the ##STR7## and where the 3β-hydroxy-Δ⁵ steroid (C) is protected as the ##STR8## where R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom;

M is a lithium, sodium, potassium, magnesium or calcium atom; and

W is a TMS, THP, or ethoxy ethyl group.

7. An enimide according to Enumerated Embodiment 5 where Z is selected from the group consisting of EEE, THP, TMS, and MEM.

8. An enimide according to Enumerated Embodiment 5 where R₂₀ is selected from the group consisting of acetyl, propionyl, benzoyl, formyl, trichloroacetyl, and trifluoroacetyl.

9. An enimide according to Enumerated Embodiment 5 which is selected from the group consisting of 17α-(α-ethoxyethyl)-ether-20-acetylaminopregn-5-en-3-ethylidine ketal, and 17α-(α-ethoxyethyl)-ether-20-trifluoroacetylamino-pregn-5-ene-3-ethylidine ketal.

10. A process for the preparation of a C₃ protected form of an enimide of the formula ##STR9## which comprises

(1) contacting a C₃ protected form of a 17-protected-17β-cyano-17α-hydroxy steroid of the formula ##STR10## with a methylating agent and

(2) contacting the product of step (1) with an acylating or silating agent where

R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

R₂₀ is --OC--R₂₀ ' or --R₂₀ ";

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups;

R₂₀ " is --Si(CH₃)₃ or --SI(CH₃)₂ C(CH₃)₃ ;

X refers to a hydrogen atom or nothing;

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group;

is a single or double bond; and

˜ indicates that the attached atom or group can be in either the a or β configurations.

11. A process according to Enumerated Embodiment 10 where the Δ⁴ -3-keto steroid (A) is protected as the ##STR11## where the ΔHU 1,4-3-keto steroid (B) is protected as the ##STR12## and where the 3β-hydroxy-Δ⁵ steroid (C) is protected as the ##STR13## where R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom;

M is lithium, sodium, potassium, magnesium or calcium atom; and

W is a TMS, THP, or ethoxy ethyl group.

12. A process according to Enumerated Embodiment 10 where the methylating agent is selected from the group consisting of methyl lithium, methyl magnesium bromide, methyl magnesium chloride and methyl magnesium iodide.

13. A process according to Enumerated Embodiment 10 where the acylating or silating agent is selected from the group consisting of (R₂₀)₂ O, R₂₀ J, or R₂₀ "J where

R₂₀ " is --Si(CH₃)₃ or --Si(CH₃)₂ C(CH₃)₃ and where

J is a chlorine, bromine or iodine atom.

14. A process according to Enumerated Embodiment 13 where the acylating agent is acetic anhydride or acetyl chloride.

15. A process for the preparation of a C₃ protected form of a Δ²⁰ -enamide acylate of the formula ##STR14## which comprises contacting a steroid selected from the group consisting of a C₃ protected form of an enimide of the formula ##STR15## or a C₃ protected form of a Δ²⁰ -enamide of the formula ##STR16## with a carboxylic acid of the formula R₁₇ COOH and an anhydride of the formula (R₁₇ CO)₂ O where

R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

R₁₇ is a hydrogen atom alkyl of 1 thru 5 carbon atoms, phenyl substituted with zero thru 2 chlorine, trichloromethyl, trifluoromethyl;

R₂₀ is --OC--R₂₀ ' or --R₂₀ ";

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups;

R₂₀ " is --Si(CH₃)₃ or --SI(CH₃)₂ C(CH₃)₃ ;

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group;

X refers to a hydrogen atom or nothing;

is a single or double bond; and

˜ indicates that the attached atom or group can be in either the a or β configurations.

16. A process according to Enumerated Embodiment 15 where the Δ⁴ -3-keto steroid (A) is protected as the ##STR17## where the Δ¹,4 -3-keto steroid (B) is protected as the ##STR18## and where the 3β-hydroxy-Δ⁵ steroid (C) is protected as the ##STR19## where

R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom;

M is a lithium, sodium, potassium, magnesium or calcium atom; and

W is a TMS, THP, or ethoxy ethyl group.

17. A process according to Enumerated Embodiment 15 where R₁₇ is methyl, ethyl or phenyl.

18. A process for the preparation of a C₃ protected form of a Δ²⁰ -enamide of the formula ##STR20## which comprises contacting a C₃ -protected form of an enimide of the formula ##STR21## with an acid or base where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

R₂₀ is --OC--R₂₀ ' or --R₂₀ ";

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups;

R₂₀ " is --Si(CH₃)₃ or --SI(CH₃)₂ C(CH₃)₃ ;

X refers to a hydrogen atom or nothing;

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group;

is a single or double bond; and

˜ indicates that the attached atom or group can be in either the a or β configurations.

19. A process according to Enumerated Embodiment 18 where the Δ⁴ -3-keto steroid (A) is protected as the ##STR22## where Δ¹,4 -3-keto steroid (B) is protected as the ##STR23## and where the 3β-hydroxy-Δ⁵ steroid (C) is protected as the ##STR24## where R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom;

M is a lithium, sodium, potassium, magnesium or calcium atom; and

W is a TMS, THP, or ethoxy ethyl group.

20. A process according to Enumerated Embodiment 18 where the acid is a Lewis acid or carboxylic acid.

21. A process according to Enumerated Embodiment 20 where the acid is selected from the group consisting of acetic, propionic, benzoic or citric acid.

22. A process according to Enumerated Embodiment 18 where the base is selected from the group consisting of DBU, DBN, amidine bases of the formula ##STR25## and quanidine bases of the formula ##STR26## where R_(a) is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine;

R_(g) is R_(a), a hydrogen atom or phenyl;

R₁₀₁ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine;

R₁₀₂ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine;

R₁₀₃ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine;

R₁₀₄ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a cyclic secondary amine selected from the group consisting of piperidine, pyrrolidine and morpholine;

R₁₀₆ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a secondary amine selected from the group consisting of piperidine, pyrrolidine or morpholine with the proviso that R₁₀₆ and R₁₀₇ combined cannot have more than 14 carbon atoms; R₁₀₆ and R₁₀₇ can be combined to form a secondary cyclic amine selected from the group consisting of piperidine, pyrrolidine and morpholine;

R₁₀₇ is alkyl of 1 thru 7 carbon atoms, cycloalkyl of 5 thru 7 carbon atoms, phenyl substituted with 1 thru 3 --R₁₀₀, --OR₁₀₅ or --N(R₁₀₅)₂ where with the amine the R₁₀₅ 's can be the same or different and can be combined to form a secondary amine selected from the group consisting of piperidine, pyrrolidine or morpholine with the proviso that R₁₀₆ and R₁₀₇ combined cannot have more than 14 carbon atoms; R₁₀₆ and R₁₀₇ can be combined to form a secondary cyclic amine selected from the group consisting of piperidine, pyrrolidine and morpholine.

23. A steroid selected from the group consisting of a 21-haloenimide of the formula ##STR27## and a 21-halo-Δ²⁰ -enamide of the formula ##STR28## and C₃ protected forms thereof where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

R₂₀ is --OC--R₂₀ ' or --R₂₀ ";

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups;

R₂₀ " is --Si(CH₃)₃ or --SI(CH₃)₂ C(CH₃)₃ ;

X refers to a hydrogen atom or nothing;

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group;

is a single or double bond;

˜indicates that the attached atom or group can be in either the a or β configurations; and

Hal is a chlorine, bromine, iodine, atom.

24. A steroid according to Enumerated Embodiment 23 where the Δ⁴ -3-keto steroid (A) is protected as the ##STR29## where the Δ¹,4 -3-keto steroid (B) is protected as the ##STR30## and where the 3β-hydroxy-Δ⁵ steroid (C) is protected as the ##STR31## where R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom;

M is a lithium, sodium, potassium, magnesium or calcium atom; and

W is a TMS, THP, or ethoxy ethyl group.

25. A steroid according to Enumerated Embodiment 23 where R₉ is nothing, R₁₁ is a hydrogen atom and the C-ring contains a Δ⁹,11 double bond.

26. A steroid according to Enumerated Embodiment 23 where Z is selected from the group consisting of EEE, THP, TMS, and MEM.

27. A steroid according to Enumerated Embodiment 23 where R₂₀ is selected from the group consisting of acetyl, propionyl, benzoyl, formyl, trichloroacetyl and trifluoroacetyl.

28. A steroid according to Enumerated Embodiment 23 where Hal is a bromine atom.

29. A steroid according to Enumerated Embodiment 23 which is selected from the group consisting of 21-bromo-17α-(α-ethoxyethyl)-ether-20-acetylamino-pregna-5-en-3-ethylidine ketal and 21-bromo-17α-(α-ethoxyethyl)-ether-20-acetylamino-pregna-5,20-diene-3-ethylidine ketal.

30. A process for the preparation of a C₃ protected form of an oxazoline of the formula ##STR32## which comprises contacting a steroid selected from the group consisting of a C₃ protected form of an enimide of the formula ##STR33## or a C₃ protected form of a Δ²⁰ -enamide of the formula ##STR34## with an acid in an organic solvent or mixtures thereof where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

R₁₇ is a hydrogen atom alkyl of 1 thru 5 carbon atoms, phenyl substituted with zero thru 2 chlorine, trichloromethyl, trifluoromethyl;

R₂₀ is --OC--R₂₀ ' or --R₂₀ ";

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups;

R₂₀ " is --Si(CH₃)₃ or --SI(CH₃)₂ C(CH₃)₃ ;

X refers to a hydrogen atom or nothing;

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group;

is a single or double bond; and

˜indicates that the attached atom or group can be in either the a or β configurations.

31. A process according to Enumerated Embodiment 30 where the Δ⁴ -3-keto steroid (A) is protected as the ##STR35## where the Δ¹,4 -3-keto steroid (B) is protected as the ##STR36## and where the 3β-hydroxy-Δ⁵ steroid (C) is protected as the ##STR37## where R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom;

M is a lithium, sodium, potassium, magnesium or calcium atom; and

W is a TMS, THP, or ethoxy ethyl group.

32. A process according to Enumerated Embodiment 30 where the acid is selected from the group consisting of mineral inorganic acids, organic acids and Lewis acids.

33. A process according to Enumerated Embodiment 32 where the acid is selected from the group consisting of p-TSA, acetic, sulfuric, hydrochloric, phosphoric, formic and benzoic.

34. A process for the preparation of a steroid selected from the group consisting of a C₃ protected form of a 21-halo enimide of the formula ##STR38## and a C₃ protected form of a 21-halo-Δ²⁰ -enamide of the formula ##STR39## which comprises contacting a C₃ protected form of a Δ²⁰ -enamide of the formula ##STR40## with a halogenating agent where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine pr oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

R₂₀ is --OC--R₂₀ ' or --R₂₀ ";

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups;

R₂₀ " is --Si(CH₃)₃ or --SI(CH₃)₂ C(CH₃)₃ ;

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group;

X refers to a hydrogen atom or nothing;

is a single or double bond;

˜indicates that the attached atom or group can be in either the a or β configurations; and

Hal is a chlorine, bromine, iodine, atom.

35. A process according to Enumerated Embodiment 34 where the Δ⁴ -3-keto steroid (A) is protected as the ##STR41## where the Δ¹,4 -3-keto steroid (B) is protected as the ##STR42## and where the 3β-hydroxy-Δ⁵ steroid (C) is protected as the ##STR43## where R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom;

M is a lithium, sodium, potassium, magnesium or calcium atom; and

W is a TMS, THP, or ethoxy ethyl group.

36. A process according to Enumerated Embodiment 34 where the halogenating agent is selected from the group consisting of bromine, NBS, NCS, dibromatin, pyridine hydrobromide.

37. A process for preparing a C₃ protected form of a 17α-hydroxy steroid of the formula ##STR44## which comprises

(1) contacting a steroid selected from the group consisting of a C₃ protected form of a 21-halo enimide of the formula ##STR45## or a C₃ protected 21-halo-Δ²⁰ -enamide of the formula ##STR46## with an (aqueous) acid where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

R₂₀ is --OC--R₂₀ ' or --R₂₀ ";

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups;

R₂₀ " is --Si(CH₃)₃ or --SI(CH₃)₂ C(CH₃)₃ ;

X refers to a hydrogen atom or nothing;

Z is selected from the group consisting of a TMS, THP, methoxymethyl, t-butyl-dimethyl silyl and EEE group;

Hal is a chlorine, bromine, iodine, atom;

is a single or double bond; and

˜ indicates that the attached atom or group can be in either the a or β configurations.

38. A process according to Enumerated Embodiment 37 where the Δ⁴ -3-keto steroid (A) is protected as the ##STR47## where the Δ¹,4 -3-keto steroid (B) is protected as the ##STR48## and where the 3β-hydroxy-Δ⁵ steroid (C) is protected as the ##STR49## where R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom;

M is a lithium, sodium, potassium, magnesium or calcium atom; and

W is a TMS, THP, or ethoxy ethyl group.

39. A process according to Enumerated Embodiment 37 where the acid is an inorganic mineral acid.

40. A process according to Enumerated Embodiment 37 where the acid is sulfuric acid and the solvent is THF.

41. A Δ²⁰ -enamide acylate of the formula ##STR50## and C₃ protected forms thereof where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

R₁₇ is a hydrogen atom alkyl of 1 thru 5 carbon atoms, phenyl substituted with zero thru 2 chlorine, trichloromethyl, trifluoromethyl;

R₂₀ is --OC--R₂₀ ' or --R₂₀ ";

R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups;

R₂₀ " is --Si(CH₃)₃ or --SI(CH₃)₂ C(CH₃)₃ ;

is a single or double bond; and

˜ indicates that the attached atom or group can be in either the a or β configurations.

42. A Δ²⁰ -enamide acylate according to Enumerated Embodiment 41 where the Δ⁴ -3-keto steroid (A) is protected as the ##STR51## and where the Δ¹,4 -3-keto steroid (B) is protected as the ##STR52## where R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom; and

M is lithium, sodium, potassium, magnesium or calcium atom.

43. A Δ²⁰ -enamide acylate according to Enumerated Embodiment 41 where R₉ is nothing, R₁₁ is a hydrogen atom and the C-ring contains a Δ⁹,11 double bond.

44. A Δ²⁰ -enamide acylate according to Enumerated Embodiment 41 where R₂₀ is selected from the group consisting of acetyl, propionyl, benzoyl, formyl, trichloroacetyl and trifluoroacetyl.

45. A Δ²⁰ -enamide acylate according to Enumerated Embodiment 41 where R₁₇ is selected from the group consisting of methyl, ethyl and phenyl.

46. A Δ²⁰ -enamide acylate according to Enumerated Embodiment 41 which is 17α-acetoxy-20-acetylaminopregna-5,20-dien-3-ethylidine ketal.

47. A 17β-cyano-17α-hydroxy steroid of the formula ##STR53## and C₃ protected forms thereof where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring

(a) Δ⁹(11) when R₁₁ is a hydrogen atom,

(b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and

(c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond;

R₁₆ is a hydrogen atom or methyl group;

is a single or double bond; and

˜ indicates that the attached atom or group can be in either the a or β configurations.

48. A 17β-cyano-17α-hydroxy steroid according to Enumerated Embodiment 47 where R₉ is nothing, R₁₁ is hydrogen atom and the C-ring contains a Δ⁹(11) double bond.

49. A 17β-cyano-17α-hydroxy steroid of the formula ##STR54## and C₃ protected forms thereof where R₆ is a hydrogen or fluorine atom or methyl group;

R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring

(a) Δ⁹(11) when R₉ is nothing and

(b) 9β,11-epoxide when R₉ is an oxygen atom;

R₁₆ is a hydrogen atom or methyl group; and

˜ indicates that the attached atom or group can be in either the a or β configurations.

50. A 17β-cyano-17α-hydroxy steroid according to Enumerated Embodiment 49 which is selected from the group consisting of 17β-cyano-11β,17α-dihydroxy-androst-4-en-3-one and 17β-cyano-11β,17α-dihydroxy-6a-methylandrost-4-en-3-one. 

I claim:
 1. A steroid selected from the group consisting of 21-bromo-17α-(α-ethoxyethyl)-ether-20-acetylaminopregna-5-en-3-ethylidine ketal and 21-bromo-17α-(α-ethoxyethyl)ether-20-acetylaminopregna-5,20-diene-3-ethylidine ketal.
 2. A C₃ -protected Δ²⁰ -enamide acylate of the formula ##STR55## where the Δ⁴ -3-keto steroid (A) is protected as the ##STR56## and where the Δ¹,4 -3-keto steroid (B) is protected as the ##STR57## where R₃ is alkyl of 1 thru 5 carbon atoms with the proviso that for the ketal (Ab) and the enamine (Ac), the R₃ groups can be connected and when connected may be connected by an oxygen or nitrogen atom;R₆ is a hydrogen or fluorine atom or methyl group; R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C-ring(a) Δ⁹(11) when R₉ is nothing and (b) 9β,11-epoxide when R₉ is an oxygen atom; R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring(a) Δ⁹(11) when R₁₁ is a hydrogen atom, (b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and (c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond; R₁₆ is a hydrogen atom or methyl group; R₁₇ is a hydrogen atom alkyl of 1 thru 5 carbon atoms, phenyl substituted with 0 thru 2 chlorine, trichloromethyl, trifluoromethyl; R₂₀ is --OC--R₂₀ ' or --R₂₀ "; R₂₀ ' is alkyl of 1 thru 5 carbon atoms, phenyl, phenyl substituted 0 thru 2 chlorine atoms, methyl or nitro groups; R₂₀ " is --Si(CH₃)₃ or --Si(CH₃)₂ C(CH₃)₃ ; M is a lithium, sodium, potassium, magnesium or calcium atom; is a single or double bond; and ˜ indicates that the attached atom or group can be in either the α or β configurations.
 3. A Δ²⁰ -enamide acylate according to claim 2 where R₉ is nothing, R₁₁ is a hydrogen atom and the C-ring contains a Δ⁹,11 double bond.
 4. A Δ²⁰ -enamide acylate according to claim 2 where R₂₀ is selected from the group consisting of acetyl, propionyl, benzoyl, formyl, trichloroacetyl and trifluoroacetyl.
 5. A Δ²⁰ -enamide acylate according to claim 2 where R₁₇ is selected from the group consisting of methyl, ethyl and phenyl.
 6. A Δ²⁰ -enamide acylate according to claim 2 which is 17α-acetoxy-20-acetylaminopregna-5,20-dien-3-ethylidine ketal.
 7. A 17β-cyano-17α-hydroxy steroid of the formula ##STR58## and C₃ -protected forms thereof where R₆ is a hydrogen or fluorine atom or methyl group;R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C-ring(a) Δ⁹(11) when R₉ is nothing and (b) 9β,11-epoxide when R₉ is an oxygen atom, R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring(a) Δ⁹(11) when R₁₁ is a hydrogen atom, (b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and (c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond; R₁₆ is a hydrogen or fluorine atom or methyl group; ˜ indicates that the attached atom or group can be in either the α or β configurations.
 8. A 17β-cyano-17α-hydroxy steroid selected from the group consisting of 17β-cyano-11β,17α-dihydroxyandrost-4-en-3-one and 17β-cyano-11β,17α-dihydroxy-6α-methylandrost-4-en-3-one. 